Wealthy Culver Military Academy drop-out and playboy (lifestyle) Chris Winters (John Payne (actor)) enlists in the United States Marine Corps as a private (rank) where he meets his drill instructor Gunnery Sergeant Dixie Smith (Randolph Scott) and falls in love with a Navy nurse, Lieutenant Mary Carter (Maureen O'Hara). Smith is given a letter from Winters's father, Captain Christopher Winters (Minor Watson)' the subject of the letter is the writer's playboy son. Sgt. Smith had served in World War I under the elder Winter, and he affectionately calls Winters "The Skipper". Chris Winters cannot understand why officers and enlisted men do not associate under the non-fraternization policy, even if the officer is a woman and the enlisted man is a male.